It looks as if his foot was injured from the scrapes and swelling on top, and the green bruising in between his toes. I would soak his foot in some weak betadine, chlorhexidene, or epsom salts that was warm, and dry him well. Then put some plain Neosporin or similar on it daily. Is he limping? He would benefit from resting in pen for a couple of days with food and water.